Systems and methods for intra-consist communication

ABSTRACT

A method of communicating between a source node and a target node includes, for each of a plurality of paths between the target node and the source node, determining a total number of intermediary nodes and an expected data rate. The method also includes identifying each of the plurality of paths for which the total number of intermediary nodes is equal to or below a ceiling number as a first group of paths and identifying each of the plurality of paths for which the expected data rate is equal to or exceeds a threshold data rate as a second group of paths. A preferred path is used to communicate between the target node and the source node, the preferred path being included in the first group of paths and the second group of paths.

TECHNICAL FIELD

This disclosure relates generally to communication networks and, morespecifically, to a system and method for communicating data amonglocomotives in a consist.

BACKGROUND

Often, it is not possible or preferable for communications between twonodes in a communication network to involve a direct path between thetarget node and the source node. Sometimes, it is preferable forcommunications between two nodes to be sent via a path that includesintermediate nodes. For example, nodes associated with locomotives in aconsist may be interconnected in a linear manner and may communicatemessages between a target node and a source node via multi-hop routing.Determining which path for a communication from a source node to atarget node based upon factors such as bandwidth and the number of hopsmay increase the speed at which the communication is sent.

One proposed implementation of intra-consist communication is describedin U.S. Pat. No. 6,370,119 B1 (“the '119 patent”). The '119 patent isdirected to a system and method for determining the optimal path forrouting a communication in a communication network between a source nodeand at least one target node. The determination is based upon anevaluation of the path offering the widest bandwidth in the direction ofthe data transmission, the lowest additive cost, and the lowest hopcount. Each link of the network is associated with a least restrictivecost and an additive cost reflecting selected link characteristics. Apath is characterized by a restrictive cost and an additive cost derivedfrom the link costs of its communication links. For a connection to berouted, the system identifies a source node, a target node, and amaximum restrictive cost allowed for routing the connection. Allacceptable paths from the source node to all the other nodes of thenetwork are determined and stored. These paths are deemed acceptable andare stored if they have the lowest restrictive cost that allows therouting of the connection and if they have the lowest additive cost andminimum hop count. Finally, from the plurality of stored acceptablepaths, the path that originates from the source node and terminates atthe destination node is selected as the optimal path to route theconnection.

The method and system provided by the '119 patent may be subject to anumber of possible drawbacks. For example, the method and system of the'119 patent use a protocol that only identifies an optimal path. It maybe advantageous to identify a plurality of acceptable paths between asource node and a target node in the event that an optimal path does notfunction properly. Further, the method and system provided by the '119patent evaluate paths only based upon the communication link of the paththat has the lowest bandwidth available. That is, the method and systemof the '119 patent compare the lowest bandwidth link of two paths,preferring the path whose lowest link bandwidth is higher. It may beadvantageous to consider the bandwidth of the entire path to comparepaths to one another, rather than comparing the lowest bandwidth of acommunication link in each of the paths.

The presently disclosed systems and methods are directed to overcomingone or more of the problems set forth above and/or other problems in theart.

SUMMARY

In one aspect, this disclosure is directed to a consist. The consist mayinclude a first locomotive associated with a source node and a secondlocomotive associated with a target node. The target node may becommunicatively coupled to the source node by a plurality of paths. Theconsist may also include at least one intermediary locomotive associatedwith an intermediary node. The intermediary node may be communicativelycoupled to the source node and the target node. The consist may alsoinclude a communication controller configured to, for each of theplurality of paths, determine the total number of intermediary nodes andan expected data rate. The communication controller may also beconfigured to identify each of the plurality of paths for which thetotal number of intermediary nodes is equal to or below a ceiling valueas a first group of paths and identify each of the plurality of pathsfor which the expected data rate is equal to or above a threshold datarate as a second group of paths. The communication controller may befurther configured to identify a preferred path, wherein the preferredpath is included in the first group of paths and the second group ofpaths.

According to another aspect, this disclosure is directed to system formulti-hop routing communication between a target node and a source node.The system may include a plurality of paths communicatively connectingthe target node to the source node, wherein each of the paths includesat least one intermediary node. The system may also include acommunication controller. The communication controller may be configuredto, for each of the plurality of paths, determine a total number ofintermediary nodes and an expected data rate. The communicationcontroller may also be configured to identify each of the plurality ofpaths for which the total number of intermediary nodes is equal to orbelow a ceiling value as a first group of paths and to identify each ofthe plurality of paths for which the expected data rate is equal to orexceeds a threshold data rate as a second group of paths. Thecommunication controller may be further configured to identify apreferred path, wherein the preferred path is included in the firstgroup of paths and the second group of paths.

According to another aspect, this disclosure is directed to a method ofcommunicating between a source node and a target node. The method mayinclude, for each of a plurality of paths between the target node andthe source node, determining a total number of intermediary nodes and anexpected data rate. The method may also include identifying each of theplurality of paths for which the total number of intermediary nodes isequal to or below a ceiling number as a first group of paths andidentifying each of the plurality of paths for which the expected datarate is equal to or exceeds a threshold data rate as a second group ofpaths. A preferred path is used to communicate between the target nodeand the source node, the preferred path being included in the firstgroup of paths and the second group of paths.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 provides an exemplary embodiment of a consist.

FIG. 2 is a schematic of an exemplary communication system.

FIG. 3 is flowchart of an exemplary process of communicating databetween a source node and a target node.

DETAILED DESCRIPTION

Reference will now be made in detail to the exemplary embodimentsimplemented according to the disclosure, the examples of which areillustrated in the accompanying drawings. Wherever possible, the samereference numbers will be used throughout the drawings to refer to thesame or like parts.

FIG. 1 is a perspective view of an exemplary embodiment of a consist 10including a plurality of locomotives, such as a first locomotive 20 a,an intermediate locomotive 20 b, and a second locomotive 20 c. Althoughnot shown in FIG. 1, exemplary consist 10 may include other locomotivesin addition to first locomotive 20 a, intermediate locomotive 20 b, andsecond locomotive 20 c. Additionally, consist 10 may also include avariety of other railroad cars, such as, for example, freight cars,tender cars, and/or passenger cars and may employ different arrangementsof the cars and locomotives to suit the particular use of consist 10.

First locomotive 20 a, intermediate locomotive 20 b, and secondlocomotive 20 c may be any electrically powered rail vehicles and mayinclude any number of subsystems for operation (not shown). Suchsubsystems may include those for traction, braking, exhaust, energydistribution, and cooling. One or more control settings may beassociated with at least one of the locomotive subsystems. Such controlsettings may include powering on/off, adjusting pressure, braking force,speed, or any other feature of locomotive subsystems.

FIG. 2 is a block diagram of an exemplary embodiment of a system 22.System 22 may include a plurality of nodes. For example, the exemplaryembodiment of FIG. 2 includes five nodes, 24 a-24 e. According to someembodiments, these nodes 24 a-24 e may be associated with one or morelocomotives 20 a-20 c. For example, node 24 a may be associated withfirst locomotive 20 a, and node 24 b may be associated with intermediatelocomotive 20 b. Each of these nodes is connected to each of the othernodes, either directly or indirectly, by communication links 26 a-26 f.Communication links 26 a-26 f may include one or more types oftopologies, including bus and point-to-point connections as well aswireless topologies. That is, each node is communicatively coupled toone another by or more paths comprised of one or more communicationlinks 26 a-26 f. Those that are connected to one another indirectly areconnected via intermediary nodes. For example, node 26 b is connectedindirectly to node 24 d, by communication links 26 d and 26 e andintermediary node 24 c. Some nodes 24 a-24 e may be connected throughmultiple paths. For example, node 24 a is connected to node 24 c by atleast two paths: directly, via communication link 26 a, and indirectly,through node 24 b via communication links 26 c and 26 d.

For data communication among nodes 24 a-24 e, it may be desirable todetermine a preferred path between two nodes 24 a-24 e. To evaluatedifferent paths that connect two nodes 24 a-24 e, it may be desirable toknow how fast a particular data node 24 a-24 e or a particularcommunication link 26 a-26 f can transmit data. Nodes 24 a-24 e may berated or marketed or measured as having an actual or estimated maximumdata forwarding rate. These values may differ from one another amongnodes 24 a-24 e. Communication links 26 a-26 f may be rated or marketedor measured as having an actual or estimated maximum data forwardingrate. These values may differ from one another among communication links26 a-26 f.

Based on these and/or other factors, a communication controller 28 maybe configured to identify a preferred path between two nodes 24 a-24 e.Communication controller 28 may optionally be communicatively coupled toone or more nodes 24 a-24 e. For example, as shown in the exemplaryembodiment of FIG. 2, communication controller 28 is communicativelycoupled to nodes 24 a-24 e. Additionally or alternatively, there may bemultiple communication controllers 28, so that each of nodes 24 a-24 eare communicatively coupled to at least one communication controller 28.

FIG. 3 is a flowchart of an exemplary method 30. Method 30 may beperformed by communication controller 28 to communicate data between twonodes 24 a-24 e. For example, at step 32, method 30 may include, foreach of a plurality of paths between two nodes 24 a-24 e, determining atotal number of intermediary nodes 24 a-24 e and an expected data rate.In the exemplary path between node 24 a and node 24 c, node 24 b may bean intermediary node. The number of intermediary nodes for this exampleis one.

According to some embodiments, the expected data rate of a path may beequal to the highest data rate of the node 24 a-24 e and/orcommunication link 26 a-26 f having the lowest maximum data rate withinthat path. For example, one of the paths between node 24 a and node 24 cincludes communication links 26 c and 26 d and node 24 b. If node 24 band communication link 26 c each have a maximum data rate of 60, andcommunication link 26 d had a maximum data rate of 45, then the expecteddata rate of that path may be 45. According to some embodiments, theexpected data rate of a path may be equal to a weighted average of thedata rates of each of the nodes 24 a-24 e and communication links 26a-26 f within that path. For example, the weighted average could includefactoring in the lengths of communication links 26 a-26 f.

At step 34, method 30 may include identifying each of the plurality ofpaths for which the total number of intermediary nodes is equal to orbelow a ceiling number as a first group of paths. The ceiling number maybe a number set based on the number of nodes 24 a-24 e. Additionally oralternatively, the ceiling number may be set based on user input.According to some embodiments, the ceiling number may be the lowesttotal number of intermediary nodes 24 a-24 e. For example, one pathbetween nodes 24 a and 24 c includes node 24 b and communication links26 c and 26 d, and another path between nodes 24 a and 24 c includesonly communication link 26 a. Thus, the ceiling number may be zero, thenumber of nodes 24 a-24 e within the path having the smallest number ofintermediary nodes 24 a-24 e, which is the path including communicationlink 26 a. According to some embodiments, the ceiling number is the sumof the lowest total number of intermediary nodes and a data node margin.For example, if the data node margin is two, then in the previousexample, the ceiling number would be the sum of the lowest total numberof intermediary nodes (zero) and the data margin (two), such that theceiling number would equal two.

At step 36, method 30 may include identifying each of the plurality ofpaths for which the expected data rate equals or exceeds a thresholddata rate as the second group of paths. According to some embodiments,the threshold data rate may be the highest expected data rate of thepaths. For example, if a first path has an expected data rate of 45 andanother path has an expected data rate of 50, then the threshold datarate may be 50. According to some embodiments, the threshold data ratemay be within a predefined range of the highest expected data rate.Referring to the previous example, if the predefined range is 10%, thenthe range may be 45 to 55. According to some embodiments, the lower ofthe predefined range (45 in the example) may be the threshold data rate.

At step 38, method 30 may include sending a signal over a preferredpath, wherein the preferred path is included in the first group of pathsand the second group of paths. For example, the preferred path may bethe one with the highest expected data rate. Additionally oralternatively, the preferred path may be the one with the lowest numberof intermediary nodes. Additionally or alternatively, the preferred pathmay be selected based on a function of the expected data rates and thetotal number of intermediary nodes of each of the paths.

Additionally or alternatively, method 30 may include additionalparameters for selecting the preferred path. For example, method 30 mayinclude identifying a desired number of paths to be in both the firstand second group of paths. If the number of paths in both groups exceedsdesired number of paths, method 30 may include removing one or morepaths from one or both groups. For example, if the desired number ofpaths is four and there are five paths in both groups, method 30 mayinclude removing one path from one or both groups. For example, method30 may remove the path with the lowest expected data rate from the firstand/or second group of paths.

According to some embodiments, method 30 may include determining thepreferred path in a round-robin style. Additionally or alternatively,the preferred path may be picked at random. According to someembodiments, method 30 may include determining the Hamming distancebetween each path and a reference path. The reference path may be thepath with the highest expected data rate. Method 30 may include removingfrom at least one of the first group and the second group each path forwhich the Hamming distance is less than a preferred Hamming distancevalue.

Embodiments herein include computer-implemented methods, systems, anduser interfaces. The computer-implemented methods may be executed, forexample, by at least one processor that receives instructions from anon-transitory computer-readable storage medium. Similarly, systemsconsistent with the present disclosure may include at least oneprocessor and memory, and the memory may be a non-transitorycomputer-readable storage medium. As used herein, a non-transitorycomputer-readable storage medium refers to any type of physical memoryon which information or data readable by at least one processor may bestored. Examples include random-access memory (RAM), read-only memory(ROM), volatile memory, nonvolatile memory, hard drives, CD ROMs, DVDs,flash drives, disks, and any other known physical storage medium.Singular terms, such as “memory” and “computer-readable storage medium,”may additionally refer to multiple structures, such a plurality ofmemories and/or computer-readable storage mediums. As referred toherein, a “memory” may include any type of computer-readable storagemedium unless otherwise specified. A computer-readable storage mediummay store instructions for execution by at least one processor,including instructions for causing the processor to perform steps orstages consistent with embodiments herein. Additionally, one or morecomputer-readable storage mediums may be utilized in implementing acomputer-implemented method. The term “computer-readable storage medium”should be understood to include tangible items and exclude carrier wavesand transient signals.

INDUSTRIAL APPLICABILITY

The disclosed systems and methods provide a robust solution forintra-consist communication. For example, the presently describedsystems and methods allow preferred connections between two nodes to beidentified and used. The presently disclosed systems and methods mayhave several advantages over other attempted solutions. For example, thedisclosed systems and methods may identify a plurality of acceptablepaths between a source node and a target node in the event that anoptimal path does not function properly. Further, the disclosed systemsand methods consider the bandwidth of the entire path to compare pathsto one another rather than comparing the lowest bandwidth of aparticular communication link within the paths. This allows for a moreaccurate identification of the preferred paths.

It will be apparent to those skilled in the art that variousmodifications and variations can be made to the disclosed systems andmethods for intra-consist communication. Other embodiments of thepresent disclosure will be apparent to those skilled in the art fromconsideration of the specification and practice of the presentdisclosure. It is intended that the specification and examples beconsidered as exemplary only, with a true scope of the presentdisclosure being indicated by the following claims and theirequivalents.

What is claimed is:
 1. A consist having a plurality of locomotives,comprising: a first locomotive associated with a source node; a secondlocomotive associated with a target node, the target nodecommunicatively coupled to the source node by a plurality of paths; atleast one intermediary locomotive associated with an intermediary node,the intermediary node communicatively coupled to the source node and thetarget node via at least one path of the plurality of paths; at leastone communication controller; and memory to store instructions forexecution by the at least one communication controller, the at least onecommunication controller communicatively coupled to the memory, each ofthe source node of the first locomotive, the target node of the secondlocomotive and the intermediary node of the at least one intermediarylocomotive, the at least one communication controller configured to: foreach of the plurality of paths, determine the total number ofintermediary nodes and an expected data rate; identify each of theplurality of paths for which the total number of intermediary nodes isequal to or below a ceiling value as a first group of paths; identifyeach of the plurality of paths for which the expected data rate is equalto or above a threshold data rate as a second group of paths; identify apreferred path, wherein the preferred path is included in the firstgroup of paths and the second group of paths; and send a desiredcommunication signal over the preferred path.
 2. The consist of claim 1,wherein the preferred path has the highest expected data rate.
 3. Theconsist of claim 1, wherein the threshold data rate is the highestexpected data rate of the paths.
 4. The consist of claim 1, wherein thethreshold data rate is within a predefined range of the highest expecteddata rate.
 5. A system for multi-hop routing communication between atarget node and a source node, the system comprising: a plurality ofpaths communicatively connecting the target node to the source node,wherein each of the paths includes at least one intermediary node; atleast one communication controller; and memory to store instructions forexecution by the at least one communication controller, the at least onecommunication controller communicatively coupled to the memory, each ofthe source node, the target node and the at least one intermediary node,the at least one communication controller configured to: for each of theplurality of paths, determine a total number of intermediary nodes andan expected data rate; identify each of the plurality of paths for whichthe total number of intermediary nodes is equal to or below a ceilingvalue as a first group of paths; identify each of the plurality of pathsfor which the expected data rate is equal to or exceeds a threshold datarate as a second group of paths; identify a preferred path, wherein thepreferred path is included in the first group of paths and the secondgroup of paths; and send a desired communication signal over thepreferred path.
 6. The system of claim 5, wherein the preferred path hasthe highest expected data rate.
 7. The system of claim 5, wherein thecommunication controller is further configured to select the preferredpath by at least one of round robin and random.
 8. The system of claim5, wherein the threshold data rate is within a predefined range of thehighest expected data rate.
 9. The system of claim 5, wherein theceiling number of data nodes is the lowest total number of intermediarynodes.
 10. The system of claim 5, wherein the communication controlleris further configured to: identify a desired number of paths to beincluded in both the first and second group of paths; determine whetherthe number of paths that are in both the first and second group of pathsexceeds the desired number; and if the number of paths exceeds thedesired number, remove from at least one of the first group and thesecond group paths for which the expected data rate is the lowest of theexpected data rates of the paths in the first and second group of paths.11. The system of claim 5 wherein the communication controller isfurther configured to: for each path, determine the Hamming distancebetween the path and a reference path, wherein the reference path is thepath with the highest expected data rate; and remove from at least oneof the first group and the second group each path for which the Hammingdistance is less than a preferred Hamming distance value.
 12. A methodfor communicating between a source node and a target node, the methodcomprising: for each of a plurality of paths between the target node andthe source node, determining a total number of intermediary nodes and anexpected data rate; identifying each of the plurality of paths for whichthe total number of intermediary nodes is equal to or below a ceilingnumber as a first group of paths; identifying each of the plurality ofpaths for which the expected data rate is equal to or exceeds athreshold data rate as a second group of paths; and using a preferredpath to communicate between the target node and the source node, whereinthe preferred path is included in the first group of paths and thesecond group of paths.
 13. The method of claim 12, wherein the preferredpath has the highest expected data rate.
 14. The method of claim 12,wherein the threshold data rate is the highest expected data rate of thepaths.
 15. The method of claim 12, wherein the threshold data rate iswithin a predefined range of the highest expected data rate.
 16. Themethod of claim 12, wherein the preferred path has the lowest totalnumber of intermediary nodes.
 17. The method of claim 12, wherein theceiling number of data nodes is the lowest total number of intermediarynodes.
 18. The method of claim 12, wherein the ceiling number of datanodes is the sum of the lowest total number of intermediary nodes and adata node margin.
 19. The method of claim 12, further including:determining whether the number of paths that are in both the first andsecond group of paths exceeds a desired number; and if the number ofpaths exceeds the desired number, removing from at least one of thefirst group and the second group paths for which the expected data rateis the lowest of the expected data rates of the paths in the first andsecond group of paths.
 20. The method of claim 12, further including:for each path, determining the Hamming distance between the path and areference path, wherein the reference path is the path with the highestexpected data rate; and removing from at least one of the first groupand the second group each path for which the Hamming distance is lessthan a preferred Hamming distance value.